iPhone 4S and iOS 9: Is It Possible?

Apple released a version of iOS for the iPhone 4S, and I'm sure there are plenty of people who are nervous about installing it. This device is four years old, and four new models have come out since its release, so it's possible the iPhone 4S just isn't up to a new operating system.

Fortunately, that's not the case. I loaded iOS 9 onto a 4S on the day this new version was introduced and have been using it ever since, and have had no problems.

In fact, it's possible the device runs better with this upgrade than it did with iOS 8, which was poorly written from Day 1. Don't get me wrong, this is still an elderly phone and a new OS isn't going to turn it into a speed demon, but it's certainly no slower or more unstable than it was before... except possible the Camera app, which can take a few seconds to open.

I also installed iOS 9.0.1 when it came out a few days ago and have continued to have no significant problems.

My useful BH links"Friends: the Fambly we choose" ~Shared pain is diminished, shared joy is increased
inanimate objects are smarter than we give them credit for~our lives are too short to not help others~when you find a big kettle of crazy, it's best not to stir it Dilbert 9/22/09~ making no decision is really making the choice to do nothing, about something~organic spell-checker is nearly perfect, but sometimes, it just doesn't care.Lord, let me be the kind of person my cat (or dog) thinks I am.

Our recommendation for iPhone 4S users is pretty much the same one we gave to iPad 2 users earlier today: if you're running iOS 8, go ahead and upgrade.

If you're still running iOS 7, at this point we'd say you should probably upgrade, not because you won't take a small performance hit, but because developers will increasingly abandon that older OS version if they haven't already.
​

The Sydney Morning Herald said:

A series of videos from YouTube channel iAppleBytes compare the performance of the latest iOS against iOS 8.4.1 across several iPhones, and show that in booting up and opening apps the latest software is often a fraction of a second behind.

In the videos the issue is seen to be most pronounced on the oldest model iPhone 4s. However keeping in mind iOS 9 packs a lot of new features (and, more importantly, serious security fixes), and the 4s was released a full four years ago, a split second of lag is not unexpected.
​

I'm quite willing to believe that an iPhone 4s running iOS 9 is a split second slower than iOS 8, but I don't consider that significant, especially when compared to the advantages of the new version.